Ligament ultrasound

Ligaments are fibrillar structures that connect two bone structures. There are two types of ligaments: intra-articular and extra-articular. This difference determines a differentiated approach to their study. Since ultrasound examination of intra-articular ligaments is difficult due to bone structures, MRI is used to evaluate them. Ultrasound examination is more informative for assessing the condition of extra-articular ligaments.

Research methodology.

Ultrasound examination of ligaments should begin with identification of the two bone structures to which the ligament is attached. Having connected them with an imaginary line, the transducer is installed on the longitudinal axis of the ligament. To avoid the anisotropy effect, the ligament under examination should be perpendicular to the ultrasound beam. Here, as for tendons, linear transducers with a frequency of 7.5-15 MHz are used.

The echo is normal.

Ligaments are similar to tendons in their echostructure. Extra-articular ligaments appear as hyperechoic fibrillar structures. They are made of collagen tissue and connect one bone to another, such as the medial collateral ligament of the knee joint or the patellar ligament. However, some of them, such as the lateral collateral ligament of the knee joint,

Hypoechoic due to additional fibers running in a different direction. Intra-articular ligaments, such as the cruciate ligaments of the knee joint, are visualized as hypoechoic structures, since their course is not perpendicular to the ultrasound beam.

In transverse scanning, ligaments are often difficult to distinguish from surrounding tissues, so they are scanned parallel to their long axis. On MRI, ligaments have low intensity in T1- and T2-weighted images.

Ligament pathology.

Sprains and ruptures. Sprains and ruptures of ligaments occur when the range of motion in a joint is excessively increased. The ligaments of the knee joint are most often damaged. The degree of ligament damage may vary: from a sprain, partial rupture to a complete rupture with a bone fragment being torn off. With sprains, the integrity of the ligament may be preserved, but thickening due to edema may be observed at the site of the sprain. There may be intra-trunk and partial marginal ruptures of ligament fibers both at the site of its attachment to the bone and in its central part. In this case, the function of the ligament may be partially preserved.

Treatment for intra-trunk ruptures is symptomatic with limitation of active movements in the joint. In case of incomplete marginal ruptures, immobilization is required for a period of 2-3 weeks and limitation of loads on the joint for 4 months. In case of significant damage, complete ruptures of the ligaments occur with complete loss of ligament function. A hematoma and edema of the surrounding tissues appear at the rupture site. In the absence of restorative treatment, the ruptured fiber zone is replaced by a scar, which leads to instability in the joint, development of degenerative changes and repeated injuries. Treatment consists of repositioning the fibers of the ruptured ligament. Thus, it is important not only to diagnose a ligament rupture, but also to determine its degree, as this affects the choice of treatment tactics.

"Jumper's knee". Local tendinitis is common with repetitive strain in jumpers, long-distance runners, volleyball players, and basketball players. It is called "jumper's knee" and "inverted jumper's knee". In this case, the ligament thickens either at its attachment to the patella or at its attachment to the tibia, respectively. Ligament damage is associated with effusion in the infrapatellar bursa.

Chronic tendinitis easily causes ligament ruptures. With a complete rupture, the fibrillar structure of the ligament disappears, a hematoma appears in its place, as well as effusion into the subpatellar bursa. With a partial rupture, the fibrillar structure of the ligament is partially preserved. With chronic tendinitis, calcifications and fibrosis areas appear at the site of attachment of the ligament to the bone.

Ostuden-Schlatter disease. This is a type of chondropathies affecting the patellar ligament and the tuberosity of the tibia. It occurs as a result of repeated microtraumas. With this disease, the patient experiences spontaneous pain that intensifies when bending the knee joint. The distal part of the patellar ligament thickens and hypoechoic areas with fragments of the anterior tuberosity of the tibia are determined in it. The ultrasound signs are the same as with ligament inflammation, but with this pathology there are bone inclusions in the ligament.